Skin cleansing today has become a demanding, fragmented market that requires sophisticated products having a variety of appearances and textures. Clear formulas with suspended particles, beads or capsules, for aesthetic or functional benefits are more and more common. Mild cleansing products for sensitive skin are also a trend, and are usually based on sulfate-free formulas. Cleansers with added skin moisturizing and nourishing benefits, which often contain significant amounts of natural oils, are also growing areas, and as consumers expect such products to provide benefits beyond cleansing, the line between shower/bath products and skin care becomes blurred.
Beyond these trends, another focus for most product manufacturers is to lower the overall actives content in formulas—particularly in high-performance formulas, where lower surfactant levels are desired for economical and environmental reasons. The challenge for formulators is to achieve a significant reduction in the production cost while maintaining satisfactory performance for the consumer. This often involves incorporating performance additives in innovative, cost-effect ways to help compensate for the loss of certain attributes that necessarily follows from dilution.
Rheological solutions have continuously evolved to support these various needs. For conventional formulas, a number of commercial actives has been developed to impart viscosity, suspending power or both, based mainly on natural gums or synthetic polymers, which will be detailed later. However, to date, there is a clear gap between the available technological solutions and their successful application for specific textures, i.e., thickening, suspending and shear-thinning, without a negative impact on aesthetic benefits such as transparency; or performance attributes such as foam generation, cleansing and care.
The present article describes a hydrophobically-modified alkali swellable emulsion (HASE) polymer, polyacrylate-33, which was designed to close this gap. It abilities to solve formulating challenges especially in low-surfactant cleansing formulations, i.e., 6-13%, was assessed by viscosimeter and rheometer readings, UV/VIS spectrometer, foam readings and sensory testing.